code: def load_tests(loader, tests, ignore):
      tests.addTests(doctest.DocTestSuite(visualization))
      return tests
  
file_path: texthero/tests/test_visualization.py
imports: import string
  import pandas
  import doctest
  from texthero import visualization
  from .None import PandasTestCase
label_desc: Use image node_id 1 for calling a global function with example usage: load_tests(loader, tests, ignore) and returns: tests